China, the world's largest crude importer and Iran's top customer, bought an average of 1.05 million barrels per day (bpd) of Iranian oil in the first 10 months of 2023, according to shiptracking data from Vortexa. This is 60% above pre-sanction peaks recorded by Chinese customs in 2017.
Tehran's October output edged up to 3.17 million bpd, the highest since 2018, when Washington re-imposed sanctions on Iran, according to Reuters surveys and OPEC figures.
China's October imports from Iran are estimated to have reached around 1.45 million bpd, the highest monthly level ever, Vortexa data showed.
Most of the more than 40 independent Chinese refiners, known as teapots, process Iranian oil, according to Chinese traders. Teapots have little exposure to the dollar-based global financial system and don't need to cooperate with Western firms on technology.
China also buys crude from Russia and Venezuela - which have also faced US sanctions. Beijing has long opposed unilateral sanctions and has said its normal trade deserves respect and protection.
SD/PR